A guanidine compound, a preparation method and application thereof

Abstract

The present application provides a kind of guanidine compound and its preparation method and application, the guanidine compound is amino guanidine group modified MOF derivative, guanidine compound has formula 1 structure formula, R1,R2 Each is independently selected from H, C1-C3 alkyl;R3 is selected from C1-C3 alkylene, C2-C3 alkenylene;M is selected from 0, 1 or 2;R4 is selected from H or methyl;R5 is selected from methyl or H;MOF is the metal organic framework compound containing amino functional group, selected from MIP-202 or NH2-UiO-66.The guanidine compound provided in the present application has the advantages of low regeneration temperature, high adsorption capacity and no corrosion when used as a carbon dioxide adsorbent.

Description

Technical Field

[0001] This invention relates to a guanidine compound, and more particularly to a guanidine compound, its preparation method, and its application, belonging to the field of gas adsorption and separation. Background Technology

[0002] Currently, the extreme weather and environmental pollution problems caused by the greenhouse effect are becoming increasingly prominent. Carbon emissions from fossil fuel combustion and various industrial waste gases are the main contributors to the increase in carbon dioxide emissions. Therefore, carbon capture in industrial settings is an important means to achieve the zero-carbon goal.

[0003] Currently, the more mature carbon capture technologies include post-combustion chemical absorption and pre-combustion physical absorption, generally referred to as first-generation technologies. These technologies are primarily based on solution-phase adsorption systems. Through gas-liquid two-phase contact between flue gas and the reaction liquid, the alkali or amine in the solution reacts with carbon dioxide, capturing it in the solution. After further processing, the captured carbon dioxide is released through vacuum, pressurization, or heating to obtain high-purity carbon dioxide gas with reuse or storage value. Although this type of capture technology has high carbon dioxide adsorption efficiency, it still faces some issues requiring improvement: First, the regeneration enthalpy of this system is high, requiring significant energy consumption and increasing operating costs; second, the solution-phase system inevitably faces corrosion problems on the reaction equipment, placing higher demands on the corrosion resistance of the equipment materials and correspondingly increasing equipment maintenance costs; finally, due to the harsh regeneration conditions, the active substances in the system are easily decomposed and deactivated under high pressure or high temperature conditions.

[0004] Therefore, there is an urgent need to develop a solid carbon dioxide adsorbent with low regeneration temperature, high adsorption capacity, and no corrosiveness. Summary of the Invention

[0005] This invention provides a guanidine compound, which, as a solid carbon dioxide adsorbent, has advantages such as low regeneration temperature, high adsorption capacity, and non-corrosiveness.

[0006] This invention provides a method for preparing guanidine compounds, which can produce guanidine compounds with low regeneration temperature, high adsorption capacity, and non-corrosiveness. The method also has the advantages of simple process and low equipment requirements.

[0007] The present invention also provides a carbon dioxide adsorbent with low regeneration temperature, high adsorption capacity and environmental friendliness.

[0008] The present invention also provides a method for adsorbing carbon dioxide, which enables rapid adsorption of carbon dioxide.

[0009] This invention provides a guanidine compound, wherein the guanidine compound is an aminoguanidine-modified MOF derivative, and the guanidine compound has the structural formula shown in Formula 1:

[0010]

[0011] Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2; R4 is selected from H or methyl; R5 is selected from methyl or H; the MOF is a metal-organic framework compound containing an amino functional group, selected from MIP-202 or NH2-UiO-66.

[0012] In the guanidine compounds described above, R1 and R2 are each independently selected from H and C1-C2 alkyl groups; R3 is selected from C1-C2 alkylene groups; and m is selected from 0 or 1.

[0013] The guanidine compounds described above are obtained by a preparation method comprising the following process:

[0014] Zirconium compounds are refluxed with aspartic acid or 2-aminoterephthalic acid to obtain an intermediate. The intermediate is then heated and reacted with a dicarbonyl compound having the structure of Formula 2 and a compound having the structure of Formula 3 to obtain the guanidine compounds.

[0015]

[0016] Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2;

[0017]

[0018] Wherein, R4 is selected from H or methyl; R5 is selected from methyl or H; and n is selected from 0 or 1.

[0019] This invention provides a method for preparing the guanidine compound as described above, comprising the following steps:

[0020] 1) The zirconium compound is reacted with aspartic acid or 2-aminoterephthalic acid under reflux to obtain the intermediate;

[0021] 2) The intermediate is stirred with a dicarbonyl compound having the structure of Formula 2, and then a solution of a compound having the structure of Formula 3 is added and heated to obtain the guanidine compound.

[0022] In the method for preparing guanidine compounds as described above, the molar ratio of the intermediate, the dicarbonyl compound having the structural formula 2, and the compound having the structural formula 3 is 1:(0.5-10):(0.5-10).

[0023] In the preparation method of guanidine compounds as described above, the reaction temperature of the heating reaction in step 2) is 40-85℃, and the reaction time is 0.5-8h.

[0024] The present invention also provides a carbon dioxide adsorbent, wherein the carbon dioxide adsorbent comprises guanidine compounds as described above.

[0025] The present invention also provides a method for adsorbing carbon dioxide, wherein the carbon dioxide adsorbent described above is used to adsorb carbon dioxide.

[0026] In the carbon dioxide adsorption method described above, the carbon dioxide adsorbent is activated before adsorption: the carbon dioxide adsorbent is vacuum heated at 100-150°C for 1-5 hours.

[0027] The guanidine compound provided by this invention has a specific chemical structure. The (aminoguanidine) group in this guanidine compound can bind to carbon dioxide, and the imine N atom in the (aminoguanidine) group is the active site for nucleophilic reactions, adsorbing carbon dioxide through electrostatic interactions. Simultaneously, the amino groups within the MOF can chemisorb carbon dioxide. Because these interactions are relatively weak, the material exhibits low-temperature regeneration properties. Furthermore, the guanidine compound is in a solid state with a loose, porous structure, thereby enhancing its adsorption capacity, avoiding corrosion of reaction equipment, and facilitating recycling.

[0028] The method for preparing guanidine compounds provided by this invention involves the condensation of amino and carbonyl groups to produce guanidine compounds with specific functional groups. These guanidine compounds have the advantages of low regeneration temperature and high adsorption capacity. Furthermore, the preparation method is simple, requires minimal equipment, uses few types of raw materials, and the raw materials are readily available.

[0029] The carbon dioxide adsorbent provided by this invention is prepared based on the above-mentioned guanidine compounds. This carbon dioxide adsorbent has high adsorption capacity and low-temperature regeneration performance, and is environmentally friendly.

[0030] The carbon dioxide adsorption method provided by this invention enables rapid adsorption of carbon dioxide. Attached Figure Description

[0031] Figure 1 The results are FTIR tests of the guanidine compounds in Example 1 and aminoguanidine hydrochloride in Comparative Example 3.

[0032] Figure 2 BET plots for MIP-202 in Comparative Example 2 and the guanidine compound in Example 1;

[0033] Figure 3 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1 and 2.

[0034] Figure 4 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1 and 3.

[0035] Figure 5 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1, 4, and 5.

[0036] Figure 6 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1, 6, and 7.

[0037] Figure 7 The carbon dioxide adsorption curves are for the guanidine compound of Example 1, the guanidine compound of Comparative Example 1, MIP-202 of Comparative Example 2, and aminoguanidine hydrochloride of Comparative Example 3.

[0038] Figure 8 This is a comparison of the amount of carbon dioxide adsorbed by the guanidine compound in Example 1 before and after regeneration at 120°C for 1 hour. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] This invention provides a guanidine compound, which is an aminoguanidine-modified MOF derivative, and the guanidine compound has the structural formula shown in Formula 1:

[0041]

[0042] Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2; R4 is selected from H or methyl; R5 is selected from methyl or H; the MOF is a metal-organic framework compound containing an amino functional group, selected from MIP-202 or NH2-UiO-66.

[0043] In this invention, R1 and R2 are each independently selected from H and C1-C3 alkyl groups, wherein C1-C3 alkyl groups refer to chain alkyl groups having 1-3 carbon atoms or cycloalkyl groups having 3 carbon atoms. When specified as a hydrocarbon group having a specific number of carbon atoms, it includes all geometric isomers having that number of carbon atoms. In this invention, R1 and R2 can each be independently selected from -CH3, -CH2CH3, etc.

[0044] In this invention, R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; wherein, C1-C3 alkylene groups refer to alkylene groups with 1-3 carbon atoms or cycloalkylene groups with 3 carbon atoms; and C2-C3 alkenyl groups refer to alkenyl groups with 2-3 carbon atoms or cycloalkenyl groups with 3 carbon atoms. When specified as a hydrocarbon group with a specific number of carbon atoms, it includes all geometric isomers having that number of carbon atoms. R3 in this invention can be selected from -CH2-, -CH2CH2-, -CH=CH-, etc.

[0045] In this invention, R4 is selected from H or methyl; R5 is selected from methyl or H; MOF is a metal-organic framework compound containing an amino functional group, selected from MIP-202 or NH2-UiO-66.

[0046] According to the above-described scheme provided by the present invention, the guanidine compound is used as a solid carbon dioxide adsorbent, which has advantages such as low regeneration temperature, high adsorption capacity, and non-corrosiveness. The inventors analyzed the principle behind this and believe that the reason may be that, on the one hand, the guanidine compound can combine with carbon dioxide, and the imine N atom in the (aminoguanidine) group is the active site for nucleophilic reactions, reacting to generate guanidine-CO3-(H2O). x The (x is 1 or 2) structure allows for the adsorption of carbon dioxide through electrostatic interactions, while the amino groups within the MOF can chemically adsorb carbon dioxide. Furthermore, the relatively weak interaction between the (aminoguanidine) group, amino group, and carbon dioxide enables the guanidine compound to exhibit low-temperature regeneration properties. On the other hand, the solid nature of the guanidine compound provides resistance to water competition, preventing interference from moisture in carbon dioxide adsorption. Its porous structure allows the guanidine groups to bind with carbon dioxide as much as possible, increasing the adsorption capacity. Simultaneously, it can physically adsorb unbonded guanidine-containing compounds through hydrogen bonding, retaining these compounds within the MOF pores and further enhancing the adsorption capacity. Moreover, the solid carbon dioxide adsorbent avoids corrosion of reaction equipment, and its recovery process is simple, reducing process costs, simplifying the process flow, and shortening process time.

[0047] In one specific embodiment, R1 and R2 are each independently selected from H and C1-C2 alkyl groups; R3 is selected from C1-C2 alkylene groups; and m is selected from 0 or 1. When R1 and R2 are each independently selected from the above functional groups, guanidine compounds have the advantages of low regeneration temperature and high adsorption capacity.

[0048] In one specific embodiment, the guanidine compound is obtained by a preparation method comprising the following process:

[0049] Zirconium compounds are refluxed with aspartic acid or 2-aminoterephthalic acid to obtain an intermediate. The intermediate is then heated with a dicarbonyl compound having the structure of Formula 2 and a compound having the structure of Formula 3 to obtain guanidine compounds.

[0050]

[0051] Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2;

[0052]

[0053] Wherein, R4 is selected from H or methyl; R5 is selected from methyl or H; and n is selected from 0 or 1.

[0054] Specifically, zirconium compounds are first refluxed with aspartic acid or 2-aminoterephthalic acid to obtain an intermediate. Then, the intermediate is heated and reacted with a dicarbonyl compound having the structure of Formula 2 and a compound having the structure of Formula 3 to obtain guanidine compounds.

[0055] This invention does not limit the specific selection of zirconium compounds; they can be selected according to actual needs.

[0056] This invention does not limit the specific parameters of the reflux reaction; they can be selected according to actual needs.

[0057] This invention does not limit the specific parameters of the heating reaction; they can be selected according to actual needs.

[0058] The method for preparing guanidine compounds of the present invention involves the condensation of an amino group and a carbonyl group, linking a dicarbonyl compound having the structure of Formula 2 to a compound containing an (aminoguanidine) group and an amino-containing MOF to generate guanidine compounds. The guanidine compounds prepared by this method exhibit low regeneration temperature, high adsorption capacity, and non-corrosiveness.

[0059] The present invention also provides a method for preparing the guanidine compound as described above, comprising the following steps:

[0060] 1) A zirconium compound is refluxed with aspartic acid or 2-aminoterephthalic acid to obtain an intermediate;

[0061] 2) The intermediate and the dicarbonyl compound having the structure of Formula 2 are stirred together, and then a solution of the compound having the structure of Formula 3 is added and heated to react, thereby obtaining guanidine compounds.

[0062] Specifically, in step 1), zirconium compounds are stirred with aspartic acid or 2-aminoterephthalic acid, mixed evenly, and then refluxed. After cooling to room temperature, the reaction solution is subjected to solid-liquid separation to obtain a crude solid product. The crude solid product is then washed and dried to obtain an intermediate.

[0063] This invention does not limit the specific selection of zirconium compounds, which can be chosen according to actual needs. For example, zirconium tetrachloride can be selected as a zirconium compound.

[0064] This invention does not impose special limitations on the stirring rate and stirring time of the stirring process, and can be selected according to actual needs.

[0065] This invention does not impose special limitations on the reflux temperature and reflux time of the reflux reaction, and they can be selected according to actual needs. For example, the reflux temperature is 120°C and the reflux time is 1 hour.

[0066] This invention does not impose any special limitations on the method of solid-liquid separation; for example, filtration, precipitation, and other methods may be used.

[0067] The present invention does not impose any special limitations on the cleaning and drying method. For example, hot water / ethanol can be used for washing and air drying.

[0068] Step 2) The intermediate and the dicarbonyl compound having the structure of Formula 2 are stirred and mixed evenly. Then, a solution of the compound having the structure of Formula 3 is added and heated to react at a certain temperature. After the heating reaction is completed, solid-liquid separation is performed to obtain a solid crude product. The solid crude product is then washed and dried to obtain a guanidine compound.

[0069] This invention does not limit the specific selection of dicarbonyl compounds having the structure of Formula 2, and the selection can be made according to actual needs. For example, dicarbonyl compounds having the structure of Formula 2 may include acetone aldehyde, glyoxal, 2,3-butanedione, etc.

[0070] This invention does not limit the specific selection of compounds having the Formula 3 structure, and can be selected according to actual needs. For example, compounds having the Formula 3 structure may include aminoguanidine hydrochloride (CAS No.: 16139-18-7), methylaminoguanidine (CAS No.: 130659-13-1), etc.

[0071] This invention does not impose special limitations on the stirring rate and stirring time of the stirring process, and can be selected according to actual needs. For example, stirring can be carried out at a rate of 50-2000 r / min for 0.1-24 h.

[0072] This invention does not limit the choice of solvent for forming a solution of a compound having the structure of Formula 3, as long as it can form a solution of a compound having the structure of Formula 3. For example, ethanol or the like can be chosen as the solvent.

[0073] This invention does not impose special limitations on the reaction temperature and reaction time of the heating reaction, and can be selected according to actual needs.

[0074] This invention does not impose any special limitations on the method of solid-liquid separation; for example, filtration, precipitation, and other methods may be used.

[0075] The present invention does not impose any special limitations on the cleaning and drying method. For example, a Soxhlet extractor can be used to treat the sample in ultrapure water for 6 hours, followed by centrifugation and drying.

[0076] The method for preparing guanidine compounds of the present invention involves the condensation of an amino group and a carbonyl group, linking a dicarbonyl compound having the structure of Formula 2 to a compound containing an (aminoguanidine) group and an amino-containing MOF to generate guanidine compounds. The guanidine compounds prepared by this method exhibit low regeneration temperature, high adsorption capacity, and non-corrosiveness. Furthermore, this preparation method has advantages such as simple process, low equipment requirements, and uses few and readily available raw materials, thus enabling its application in large-scale guanidine compound production processes.

[0077] Specifically, the chemical structures of the guanidine compounds of the present invention were obtained by XRD, FTIR, BET, and SEM tests.

[0078] In one specific embodiment, the molar ratio of the intermediate, the dicarbonyl compound having the structure of Formula 2, and the compound having the structure of Formula 3 is 1:(0.5-10):(0.5-10), for example, molar ratios of 1:0.5:0.5, 1:0.5:1, 1:0.5:3, 1:0.5:5, 1:0.5:8, 1:0.5:10, 1:1:0.5, 1:1:1, 1:1:2, 1:1:3, 1:1:4, 1:1:6, 1:1:8, 1:1:10, 1:2:0.5, 1:2:1, 1:2:2. 1:2:3, 1:2:4, 1:2:6, 1:2:8, 1:2:10, 1:3:0.5, 1:3:1, 1:3:2, 1:3:3, 1:3:4, 1:3:8, 1:3:10, 1:4:1, 1:4:2, 1:4:3, 1:4:4, 1:4:10, 1:5:0.5, 1:5:5, 1:5:10, 1:6:0.5, 1:6:5, 1:6:10, 1:8:0.5, 1:8:5, 1:8:10, 1:10:0.5, 1:10:5, or 1:10:10, etc. When the molar ratio of the intermediate, the dicarbonyl compound having the structure of Formula 2, and the compound having the structure of Formula 3 is within the above range, the intermediate, the dicarbonyl compound having the structure of Formula 2, and the compound having the structure of Formula 3 can react fully to prepare guanidine compounds with high guanidine content, and can avoid the waste of raw materials due to excessive raw materials, thus saving costs.

[0079] In one specific embodiment, the reaction temperature for the heating reaction is 40-85°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, or 85°C, and the reaction time is 0.5-8 hours, for example, 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours. When the reaction temperature and reaction time are within the above ranges, the dicarbonyl compound having the structure of Formula 2 can be successfully linked to a compound containing an (aminoguanidine) group and an amino-containing MOF, thereby generating guanidine compounds with specific functional groups. Furthermore, the reaction at this temperature requires less equipment and saves energy, laying the foundation for the large-scale production of guanidine compounds.

[0080] The present invention also provides a carbon dioxide adsorbent comprising the aforementioned guanidine compounds. Using this guanidine compound as a carbon dioxide adsorbent results in a low regeneration temperature, high adsorption capacity, and environmental friendliness.

[0081] This invention also provides a method for adsorbing carbon dioxide, using the aforementioned carbon dioxide adsorbent to adsorb carbon dioxide. The carbon dioxide adsorption method provided by this invention enables rapid adsorption of carbon dioxide.

[0082] In one specific embodiment, the carbon dioxide adsorbent undergoes activation treatment before carbon dioxide adsorption: the carbon dioxide adsorbent is vacuum heated at 100-150℃ for 1-5 hours, for example, heating temperatures of 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, or 150℃, and heating times of 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours. This activation treatment removes moisture and impurities from the pores of the carbon dioxide adsorbent, ensuring sufficient exposure of the carbon dioxide adsorption sites, thereby guaranteeing the full utilization of the adsorption capacity of the carbon dioxide adsorbent and achieving rapid carbon dioxide adsorption. Furthermore, the low activation temperature reduces the requirements for the activation equipment, which is beneficial for the rapid progress of carbon dioxide adsorption.

[0083] The present invention will be further described in detail below through specific embodiments.

[0084] Example 1

[0085] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0086] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0087] 2. 10g MIP-202 and 40mmol acetone aldehyde were stirred for 4h. Then, aminoguanidine hydrochloride solution was added and heated at 65℃ for 1h. After the reaction was completed, the mixture was centrifuged. The precipitate was treated in ultrapure water for 6h using a Soxhlet extractor, then centrifuged and dried to obtain guanidine compounds.

[0088] The aminoguanidine hydrochloride solution includes 40 mmol of aminoguanidine hydrochloride and 17.6 mL of ethanol.

[0089] According to FTIR testing, this guanidine compound has the following structure:

[0090]

[0091] The molar ratio of MIP-202, acetone aldehyde, and aminoguanidine hydrochloride is 6.8:40:40.

[0092] Figure 1The FTIR test results for the guanidine compounds in Example 1 and aminoguanidine hydrochloride in Comparative Example 3 are as follows: Figure 1 As shown, the guanidine compound of Example 1 was tested at 1460 cm⁻¹. -1 The presence of a distinct carbon-nitrogen double bond vibration peak indicates the presence of a guanidine group in the reaction product, thus confirming the successful preparation of this guanidine compound.

[0093] Example 2

[0094] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0095] 1. Disperse 1.8g of aminoterephthalic acid in N,N-dimethylformamide, then add 2.3g of ZrCl4, mix well, and reflux at 120℃ for 6h. After the reaction is completed, cool to room temperature, filter the reaction solution, collect the filter residue, wash the filter residue with alternating soaking in ethanol / acetone, and dry it under vacuum at 80℃ to obtain NH2-UiO-66;

[0096] 2. 1.754 g of NH2-UiO-66 was stirred with acetone aldehyde for 4 h. Then, aminoguanidine hydrochloride solution was added and heated at 65 °C for 1 h. After the reaction was completed, the mixture was centrifuged. The precipitate was treated in ultrapure water for 6 h using a Soxhlet extractor, then centrifuged and dried to obtain guanidine compounds.

[0097] The molar ratio of NH2-UiO-66, acetone aldehyde, and aminoguanidine hydrochloride is 1:4:4.

[0098] According to FTIR testing, this guanidine compound has the following structure:

[0099]

[0100] Example 3

[0101] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0102] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0103] 2. 10g MIP-202 and 40mmol glyoxal were stirred for 4h, then aminoguanidine hydrochloride solution was added, and then heated at 65℃ for 1h. After the reaction was completed, the mixture was centrifuged, and the precipitate was treated in ultrapure water for 6h using a Soxhlet extractor, then centrifuged and dried to obtain guanidine compounds.

[0104] The molar ratio of MIP-202, glyoxal, and aminoguanidine hydrochloride is 1:4:4.

[0105] According to FTIR testing, this guanidine compound has the following structure:

[0106]

[0107] Example 4

[0108] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0109] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0110] 2. 10g of MIP-202 was stirred with acetone aldehyde for 4 hours, then aminoguanidine hydrochloride solution was added, and the mixture was heated at 65℃ for 1 hour. After the reaction was completed, the mixture was centrifuged, and the precipitate was treated in ultrapure water for 6 hours using a Soxhlet extractor. After centrifugation and drying, guanidine compounds were obtained.

[0111] The molar ratio of MIP-202, acetone aldehyde, and aminoguanidine hydrochloride is 1:1:1.

[0112] According to FTIR testing, this guanidine compound has the following structure:

[0113]

[0114] Example 5

[0115] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0116] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0117] 2. 10g of MIP-202 was stirred with acetone aldehyde for 4 hours, then aminoguanidine hydrochloride solution was added, and the mixture was heated at 65℃ for 1 hour. After the reaction was completed, the mixture was centrifuged, and the precipitate was treated in ultrapure water for 6 hours using a Soxhlet extractor. After centrifugation and drying, guanidine compounds were obtained.

[0118] The molar ratio of MIP-202, acetone aldehyde, and aminoguanidine hydrochloride is 1:0.5:0.5.

[0119] According to FTIR testing, this guanidine compound has the following structure:

[0120]

[0121] Example 6

[0122] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0123] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0124] 2. 10g of MIP-202 was stirred with acetone aldehyde for 4 hours. Then, aminoguanidine hydrochloride solution was added and heated at 40℃ for 6 hours. After the reaction was completed, the mixture was centrifuged and the precipitate was treated in ultrapure water for 6 hours using a Soxhlet extractor. After centrifugation and drying, guanidine compounds were obtained.

[0125] The molar ratio of MIP-202, acetone aldehyde, and aminoguanidine hydrochloride is 1:4:4.

[0126] According to FTIR testing, this guanidine compound has the following structure:

[0127]

[0128] Example 7

[0129] The preparation process of guanidine compounds provided in this embodiment includes the following steps:

[0130] 1. Disperse 28g of L-aspartic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain MIP-202.

[0131] 2. 10g of MIP-202 was stirred with acetone aldehyde for 4 hours, then aminoguanidine hydrochloride solution was added, and the mixture was heated at 80℃ for 0.5 hours. After the reaction was completed, the mixture was centrifuged, and the precipitate was treated in ultrapure water for 6 hours using a Soxhlet extractor. After centrifugation and drying, guanidine compounds were obtained.

[0132] The molar ratio of MIP-202, acetone aldehyde, and aminoguanidine hydrochloride is 1:4:4.

[0133] According to FTIR testing, this guanidine compound has the following structure:

[0134]

[0135] Comparative Example 1

[0136] The preparation process of the guanidine compounds provided in this comparative example includes the following steps:

[0137] 1. Disperse 24.8g of succinic acid in 100mL of water, then add 23.3g of ZrCl4, mix well, and reflux at 120℃ for 1h. After the reaction is complete, cool to room temperature, filter the reaction solution, collect the filter residue, wash and air dry the filter residue to obtain a white solid product.

[0138] 2. 10g of white solid product was stirred with 40mmol of acetone aldehyde for 4h. Then, aminoguanidine hydrochloride solution was added and heated at 65℃ for 4h. After the reaction was completed, the product was centrifuged. The precipitate was treated in ultrapure water for 6h using a Soxhlet extractor, then centrifuged and dried to obtain guanidine compounds.

[0139] The aminoguanidine hydrochloride solution includes 40 mmol of aminoguanidine hydrochloride and 17.6 mL of ethanol.

[0140] The chemical structural formula of guanidine compounds is:

[0141]

[0142] Since succinic acid-MOF lacks amino groups, and there is no amino group to condense with carbonyl groups, the aforementioned guanidine compounds remain in the pores of succinic acid-MOF through physical adsorption.

[0143] Comparative Example 2

[0144] MIP-202 was prepared using the method described in Example 1.

[0145] Comparative Example 3

[0146] Weigh out 500 mg of aminoguanidine hydrochloride for later use.

[0147] Test case

[0148] Weigh 500 mg of each of the guanidine compounds from Examples 1-7 and activate them. The activation process includes the following steps: heating the carbon dioxide adsorbent to 120°C at a heating rate of 1°C / min and then heating for 5 hours.

[0149] Weigh 500 mg of the guanidine compound of Comparative Example 1, MIP-202 of Comparative Example 2, and aminoguanidine hydrochloride of Comparative Example 3 respectively. Activate the guanidine compound of Comparative Example 1, MIP-202 of Comparative Example 2, and aminoguanidine hydrochloride of Comparative Example 3 respectively. The activation treatment includes the following steps: heat the carbon dioxide adsorbent to 40°C at a heating rate of 1°C / min and heat for 5 hours.

[0150] Subsequently, the guanidine compounds from Examples 1-7, the guanidine compound from Comparative Example 1, MIP-202 from Comparative Example 2, and aminoguanidine hydrochloride from Comparative Example 3 were refilled into carbon dioxide and then transferred to the analysis port. A vacuum treatment was then performed for at least 240 min before analysis began. After carbon dioxide adsorption for 1 h, a BET test was performed to obtain the carbon dioxide adsorption capacity C1. The carbon dioxide adsorbent was then desorbed at 100°C, 120°C, and 140°C, respectively, and carbon dioxide adsorption was continued for 1 h before the carbon dioxide adsorption capacity C1 was tested using a BET test. 100 C 120 C 140 If C 100 C 120 C 140 The temperature at which there is no significant decrease relative to C1 is the regeneration temperature of the carbon dioxide adsorbent.

[0151] Figure 2 The BET plots for MIP-202 in Comparative Example 2 and the guanidine compound in Example 1 are shown below. Figure 2 As shown, Comparative Example 2's MIP-202 has a porous structure with a specific surface area of ​​246.6680 m². 2 / g. The specific surface area of ​​the guanidine compound in Example 1 decreased by 24.85% (185.3519m²). 2 / g), indicating that the pore environment of the guanidine compound in Example 1 is different from that of MIP-202 in Comparative Example 2.

[0152] Figure 3 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1 and 2, as shown below. Figure 3As shown, the guanidine compound of Example 1 adsorbed 1.3 mmol / g (298 K, 1 bar) of carbon dioxide, with an average of 1.9 carbon dioxide ions adsorbed per unit cell. At 0.01 bar, the adsorption capacity of the guanidine compound of Example 1 was 0.1 mmol / g, indicating that the guanidine compound of Example 1 also has the ability to adsorb low concentrations of carbon dioxide; the guanidine compound of Example 2 adsorbed 1.5 mmol / g (298 K, 1 bar) of carbon dioxide.

[0153] Figure 4 The graphs show the carbon dioxide adsorption curves of the guanidine compounds in Examples 1 and 3, as shown below. Figure 4 As shown, the guanidine compound in Example 3 adsorbed 1.08 mmol / g (298 K, 1 bar) of carbon dioxide.

[0154] Figure 5 The carbon dioxide adsorption curves of the guanidine compounds in Examples 1, 4, and 5 are shown below. Figure 5 As shown, the guanidine compound in Example 4 adsorbed 1.08 mmol / g (298 K, 1 bar) of carbon dioxide; the guanidine compound in Example 5 adsorbed 1.1 mmol / g (298 K, 1 bar) of carbon dioxide.

[0155] Figure 6 The carbon dioxide adsorption curves of the guanidine compounds in Examples 1, 6, and 7 are shown below. Figure 6 As shown, the guanidine compound in Example 6 adsorbed 1.15 mmol / g (298 K, 1 bar) of carbon dioxide; the guanidine compound in Example 7 adsorbed 1.28 mmol / g (298 K, 1 bar) of carbon dioxide.

[0156] Figure 7 The carbon dioxide adsorption curves for Example 1, Comparative Example 1 (guanidine compounds), MIP-202, and aminoguanidine hydrochloride are shown below. Figure 7 As shown, the adsorption capacities of carbon dioxide for the guanidine compounds in Comparative Example 1, MIP-202, and aminoguanidine hydrochloride were 0.45 mmol / g, 0.03 mmol / g, and 0.02 (298 K, 1 bar) mmol / g, respectively, which were much lower than the carbon dioxide adsorption capacities of the guanidine compounds in Example 1.

[0157] Figure 8 This is a comparison chart of the carbon dioxide adsorption capacity of the guanidine compound in Example 1 before and after regeneration at 120°C for 1 hour, as shown. Figure 8As shown, the carbon dioxide adsorption-desorption curves of the guanidine compounds in Example 1 before and after regeneration are basically the same, and the adsorption amount is almost the same. Therefore, the reheat temperature of the guanidine compounds in Example 1 is 120°C.

[0158] Table 1

[0159]

[0160] As shown in Table 1, and through Examples 1-7 and Comparative Examples 1-3, the guanidine compounds of the present invention can efficiently adsorb carbon dioxide. This is because the guanidine compounds of the present invention have a specific chemical structure and contain a guanidine group. Furthermore, the guanidine compounds provided by the present invention also have a low regeneration temperature. In summary, the guanidine compounds provided by the present invention have high carbon dioxide adsorption capacity and low regeneration temperature, which is beneficial for their application as carbon dioxide adsorbents.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A guanidine compound, characterized in that, The guanidine compound is an aminoguanidinium-modified MOF derivative, and the guanidine compound has the structural formula shown in Formula 1: Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2; R4 is selected from H or methyl; R5 is selected from methyl or H; the MOF is a metal-organic framework compound containing an amino functional group, selected from MIP-202 or NH2-UiO-66.

2. The guanidine compound according to claim 1, characterized in that, R1 and R2 are each independently selected from H and C1-C2 alkyl groups; R3 is selected from C1-C2 alkylene groups; m is selected from 0 or 1.

3. The guanidine compound according to claim 1, characterized in that, The guanidine compounds are obtained by a preparation method comprising the following steps: Zirconium compounds are refluxed with aspartic acid or 2-aminoterephthalic acid to obtain an intermediate. The intermediate is then heated and reacted with a dicarbonyl compound having the structure of Formula 2 and a compound having the structure of Formula 3 to obtain the guanidine compounds. Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2; Wherein, R4 is selected from H or methyl; R5 is selected from methyl or H; and n is selected from 0 or 1.

4. A method for preparing a guanidine compound according to any one of claims 1-3, characterized in that, Includes the following steps: 1) The zirconium compound is reacted with aspartic acid or 2-aminoterephthalic acid under reflux to obtain the intermediate; 2) The intermediate is stirred with a dicarbonyl compound having the structure of Formula 2, and then a solution of a compound having the structure of Formula 3 is added and heated to obtain the guanidine compound; Wherein, R1 and R2 are each independently selected from H and C1-C3 alkyl groups; R3 is selected from C1-C3 alkylene groups and C2-C3 alkenyl groups; m is selected from 0, 1 or 2; Wherein, R4 is selected from H or methyl; R5 is selected from methyl or H; and n is selected from 0 or 1.

5. The method for preparing guanidine compounds according to claim 4, characterized in that, The molar ratio of the intermediate, the dicarbonyl compound having Formula 2, and the compound having Formula 3 is 1:(0.5-10):(0.5-10).

6. The method for preparing guanidine compounds according to claim 4 or 5, characterized in that, The heating reaction in step 2) is carried out at a temperature of 40-85℃ for 0.5-8h.

7. A carbon dioxide adsorbent, characterized in that, The carbon dioxide adsorbent includes the guanidine compounds according to any one of claims 1-3.

8. A method for adsorbing carbon dioxide, characterized in that, Use the carbon dioxide adsorbent according to claim 7 to adsorb carbon dioxide.

9. The carbon dioxide adsorption method according to claim 8, characterized in that, Before carbon dioxide adsorption, the carbon dioxide adsorbent is activated by vacuum heating at 100-150°C for 1-5 hours.

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